<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>2.文档流与浮动空间丢失</title>
  <style>
    div {
      width: 200px;
      height: 200px;

    }

    div:nth-of-type(1) {
      border: solid 1px red;
     /*float: left; */
    }

    div:nth-of-type(2) {
      background: blue;
      float: left;

    }
  </style>
</head>

<body>
  <div></div>
  <div></div>
</body>

</html>